Lilac: Three Weeks a Year, and the Wilting Problem

Lilac has the shortest window and the worst reputation for vase life of any flower people genuinely love. Both problems are real. One of them is fixable in about ninety seconds, and almost nobody is told how.

The season

Syringa vulgaris flowers in this region for roughly three weeks in early to mid May, sometimes starting in the last days of April in a warm spring. That is the whole local season. Before and after it, any lilac you see is Dutch greenhouse stock, forced and air-freighted, and it costs several times what the May crop does.

The colour range is better than the name suggests: the standard pale mauve, a deep purple (Charles Joly), a good white (Madame Lemoine, Beauty of Moscow, which opens from pink buds to double white), a genuine pale yellow (Primrose), and the picotee Sensation, purple edged in white, which is the one worth going out of your way for.

The scent is the point. It is the most recognisable flower fragrance in the northern spring and it fills a room without being oppressive — one of the few strongly fragrant flowers that works on a dining table.

The wilting problem, and the fix

Lilac has a reputation for collapsing within a day. The reputation is deserved for lilac handled the usual way and completely undeserved otherwise.

The cause is straightforward: a lilac stem carries a large mass of broad leaves, and those leaves transpire aggressively. The woody stem cannot draw water fast enough to supply both the leaves and the flower panicle. The leaves win, because they are closer to the water, and the flowers wilt while the foliage stays perfectly fresh.

The fix is to strip every single leaf off the stem. All of them. This looks wrong — a bare stem with a plume of flowers on the end looks unfinished, and people resist it — and it roughly triples the vase life.

Then:

• Split the woody base two inches vertically, or crush it, to expose more surface for uptake.
• Deep, warm water for the first drink — noticeably warm to the hand.
• Give it two hours in a cool dark place before arranging.
• Change the water every other day; woody stems foul it fast.

Done properly, lilac gives you five to eight days. Left with its foliage on, it gives you two.

If the bare-stem look bothers you, add foliage from something else. Any florist will do this — the leaves in a good lilac arrangement are usually not lilac leaves.

Buying it

Cut stage matters. Look for a panicle where roughly two-thirds to three-quarters of the individual florets are open. Fully closed lilac often will not open in a vase — the buds abort — and fully open lilac is already at the end. The half-open, half-budded panicle is a flower with three days behind it and five ahead.

Check the panicle for browning at the tip, which is where it starts, and press a small area of florets gently: they should feel crisp, not papery.

Also note: lilac and daffodil do not go in the same vase. Daffodil sap is toxic to a great many flowers and lilac is one of the more sensitive. If you want both, condition the daffodils separately for six hours first and then do not recut them when they go in.

Using it

Lilac is a mass flower with a very particular texture — soft, granular, cloudlike — and it needs something with a defined shape next to it or it reads as fog. Tulips, ranunculus, peonies and garden roses all work; other soft-textured material does not.

It also wants a lot of room. A tight arrangement crushes the panicles and they bruise brown at the contact points. Loose, generous, a wide-mouthed vessel.

Three or five stems in a large jug, with nothing else, is the correct way to use lilac in May and it is difficult to improve on. Our Purple and Lavender Collection works the same palette across a longer season, and Logan Circle Lilac Vogue is the arrangement to look at when lilac itself is out of window. In season, ask for it directly through the Bloom Preference Service — a three-week flower is a conversation, not a catalogue item.

Cutting from a garden

Lilac is common in older DC and Maryland gardens and it cuts well, with two rules.

Cut in the early morning, when the stem is fully hydrated overnight. Midday cutting on a warm May day gives you a stem that is already behind.

Cut back to a fork. Lilac flowers on the previous year's wood, so cutting long stems is pruning, and pruning it badly costs you next year's flowers. Take the flowering stem back to where it meets a pair of side shoots, and leave those. Do all your pruning within a few weeks of flowering finishing — cut it in August and you have removed next May.

The honest alternative

If lilac is out of season and the imported price is not worth it, the closest thing in the market is not another purple flower — it is a plume shape. Buddleia in late summer has a similar panicle and a similar scent register. Wisteria, briefly, in April. Failing those, a mass of stock gets you the fragrance and the density in the same colour range for a fraction of the price, and lasts twice as long.

None of them is lilac. But then, lilac in November is not really lilac either — the forced Dutch stems are handsome and almost scentless, and the scent was the reason.